import tkinter as tk

root = tk.Tk()

def show_listbox(*args):
    x = label.winfo_x()
    y = label.winfo_y() + label.winfo_height()
    width = label.winfo_width()
    print(x,y,width)
    # listbox.place(x=0,y=0)
    text = label.get()
    if text:
        listbox.place(x=x, y=y, width=width)
    else:
        listbox.place_forget()


label = tk.Entry(root)
label.pack()
label2 = tk.Entry(root)
label2.pack()
label.bind('<KeyRelease>', show_listbox)
listbox = tk.Listbox(root)
listbox.place(x=0,y=0)
listbox.place_forget()

l = ['babab','aaaaaa','zxczxc','hjkhjk']
for i in l:
    listbox.insert('end',i)

root.mainloop()
